A gas burner vent appliance generally includes a combustion chamber, a vent hood including a flue and an outlet pipe. In a forced draft appliance, a fan having an inlet connected to the vent hood and an outlet connected to the outlet pipe and an interior pressurized housing is also included. The flue communicates with the combustion chamber and provides an outlet for the exhaust of combustion gases and excess heat of combustion. In a forced draft appliance, the fan draws in ambient air to mix with the combustion gases passing through the flue to lower the combustion gas temperature. The mixture is subsequently drawn through the fan and vented through the outlet pipe.
It is common practice to include a monitor and control system for the appliance to monitor and/or control various aspects of the operation of the appliance. Typical of the art are those devices disclosed in the following U.S. patents:
______________________________________ Pat. No. Inventor(s) Issue Date ______________________________________ 3,447,746 C.D. Visos June 3, 1969 3,948,439 R.B. Heeger April 6, 1976 4,262,843 Omori et al. April 21, 1981 5,056,712 H.J. Enck Oct. 15, 1991 5,092,519 C.W. Staats March 3, 1992 5,158,446 J.H. Hall Oct. 27, 1992 ______________________________________
The '746 patent teaches a fuel flow control device which includes a temperature response valve for controlling gas flow to the burner to maintain a preselected water temperature.
The '439 patent teaches a sediment buildup warning device for water heaters which senses a predetermined increase in temperature above the normal operating temperature in the lower portion of the tank as the result of buildup of lime or other sediment in the bottom of the tank.
The '843 patent teaches a method and apparatus for controlling the feed amount of air for combustion in a natural draft type heating furnace. The feed amount of air for combustion is controlled based upon various measured values. The device does not detect and respond to emergency situations.
The '712 patent teaches a water heater controller including a plurality of temperature sensors which provide temperature data inputs to the processor and control unit. The controller relies on temperature measurements to control the water heater operation as a function of actual hot water usage. The controller is not designed to monitor the appliance for emergency situations.
The '519 patent teaches a control system including a fuel rate control valve, a water flow switch to control the fuel rate valve, an inlet water temperature switch to reduce fuel flow when the inlet temperature is high, a temperature switch at the water outlet to shut off fuel at a high temperature and a temperature sensor at the water outlet to regulate the fuel valve. The control system is geared solely to controlling the flow of fuel supplied to the burner.
The '446 patent teach a combination pressure and temperature limit control for an appliance which includes a draft inducer fan. The limit control device senses the presence of an obstruction in either the vent pipe or the vent hood inlet. When a reduction in air flow or undesirably high temperatures are sensed at the fan the limit control device shuts down the appliance. A draft inducer fan is required because the device works in conjunction with the fan.
Therefore, it is an object of this invention to provide a gas vent and burner monitoring system which monitors for emergency situations.
It is another object of the present invention to provide a gas vent and burner monitoring system which trips an alarm when an emergency situation is detected.
It is yet another object of the present invention to provide a gas vent and burner monitoring system which senses a clogged vent, improper vent installation or down draft.
Moreover, it is an object of the present invention to provide a gas vent and burner monitoring system which detects a malfunction of the burner system.
It is still another object of the present invention to provide a gas vent and burner monitoring system which detects an increase in pressure above normal operating levels.